Two point charges q_1 = 2.40 nC and q_2 = -6.70 nC are 0.100 {\rm{ m}} apart. Point A is midway between them; point B is 0.080 {\rm{ m}} from q_1 and...

Two point charges q_1 = 2.40 nC and q_2 = -6.70 nC are 0.100 {rm{ m}} apart. Point A is midway between them; point B is 0.080 {rm{ m}} from q_1 and 0.060 {rm m} from q_2 (the figure ). Take the electric potential to be zero at infinity. Find the potential at point A.